STUDY POPULATION: A total of 5 evaluable patients will be recruited, aged 18 or older. Eligible patients will be identified at the NCT, Department of Medical Oncology or Department of Dermatology (Prof. Enk). Patient 5 will be a patient with cutaneous metastatic melanoma. One tumor lesion will be biopsied (tumor excision) in order to evaluate the induction of apoptosis triggered by TNF-α. The staging examination according to RECIST criteria will be conducted at the radiological department of the University of Heidelberg. Patients will receive a central venous catheter for the extracorporeal treatment at the site of Prof. Quentmeyer (St. Josefskrankenhaus, Heidelberg). The OncoSorb® treatment of the patients with OncoSorb® as extracorporeal immune apheresis device will be conducted either at the site of Prof. Rohmeiss (ze:ro dialysis center Schwetzingen) or at the site of Prof. Zeier (Nierenzentrum Heidelberg). For security reasons the recruitment of patients will be in consecutive order for patients 1 and 2: Patient 2 can be recruited only in the case that patient 1 has finalized OncoSorb treatments until the end of cycle 2. For the recruitment of subsequent patients (patients 3 to 5), no consecutive recruitment is planned. Patient 5 will optionally receive another biopsy (tumor excision) on day 5 of week 3 of the second treatment cycle to evaluate the biological effect of the OncoSorb treatment with respect to induction of apoptosis in response to TNF-α.